This invention relates to a variable capacity compressor provided with a capacity-indicating device, and more particularly to a variable capacity compressor of this kind in which the capacity of the compressor is controlled by a control element rotatably arranged therein.
Recently, there has been a demand for a variable capacity compressor for an air conditioning system, which is provided with a device for visually indicating the compressor capacity so that the user of the compressor, such as the driver of an automotive vehicle in which the system in installed, can recognize the compressor capacity, and which is thus enhanced in commercial value.
To this end, a variable capacity compressor has been proposed, e.g. by Japanese Provisional Utility Model Publication (Kokai) No. 62-176010, which is provided with means for setting the compressor capacity at human will (e.g. a capacity-setting switch which is manually operated for setting the capacity of the compressor). According to the proposed compressor, the position of the means or setting switch humanly selected is sensed, and the sensed position of the switch, which represents the compressor capacity, is utilized as a signal for visually indicating the compressor capacity.
However, the position of the above capacity-setting switch merely indicates a level of the compressor capacity desired by the driver or the passenger who eperates the setting switch, but does not directly represent the capacity to which the compressor has been actually controlled. Further, the position of the capacity-setting switch is changed in a discontinuous manner, i.e. the switch can only be selectively set to a limited number of predetermined positions, so that it is impossible to indicate the change in the compressor capacity in a continuous or stepless manner.
Further, the above-described conventional technique can be applied only to a type of variable capacity compressor the capacity of which is adjusted from the outside (by humanly operating the capacity-setting switch). Therefore, it has been impossible to indicate the compressor capacity of a type of variable capacity compressor the capacity of which is automatically controlled in response to suction pressure of the compressor etc.